How send HSV value to color picker?
You can use the mathutils.Color type to convert HSV to RGB:

from mathutils import Color

c = Color()
c.hsv = 0.0833, 0.4, 0.5

print(c)
# roughly Color((0.5, 0.4, 0.3))


If you want to assign the color to a RGBA property (4 floats), you need to either do:

bpy.context.object.color = c.r, c.g, c.b, 1.0 # 1.0 is alpha


or a bit ugly looking tuple concatenation:

bpy.context.object.color = c[:] + (1.0,)


Alternatively, import the Python standard library module colorsys and use its conversion functions:

import colorsys

colorsys.hsv_to_rgb(0.0833, 0.4, 0.5)
# (0.5, 0.39996, 0.3)